There is known an electrophotographic image forming apparatus such as a laser printer and an LED printer. Such an image forming apparatus uses a developing cartridge. The developing cartridge includes a developing roller for supplying toner.
Prior art discloses a developing cartridge of a type that is inserted into a drawer unit. The drawer unit includes photosensitive drums. When a plurality of the developing cartridges are inserted into the drawer unit, the developing cartridges face the photosensitive drums, respectively. Then, the drawer unit attached with the developing cartridges is accommodated inside the image forming apparatus.
Another prior art discloses a developing cartridge of another type that is inserted into a drum unit. The drum unit includes a photosensitive drum. When the developing cartridge is inserted into the drum unit, the photosensitive drum and developing cartridge face each other. Then, the drum unit attached with the developing cartridge is attached to the image forming apparatus.